The fourth-seeded Trojans topped fifth-seeded Calfiornia, 70-56, in Thursday's quarterfinals of the Pacific Life Pac-10 Tournament at Staples Center.

The Trojans advance to Friday's semifinals to play the winner of top-seeded Arizona and ninth-seeded Oregon State, who tip off at 2:40 p.m. PST at Staples.

USC split the two-game regular-season series with both of those teams, as it had done with California entering Thursday's rematch. But for as close as USC's games were against the Golden Bears in both of those games this season -- each was decided by three points or fewer -- this one wasn't close.

With 11 minutes, 30 seconds left in the first half, California led, 11-3; USC was one for 10 from the floor and had five turnovers.

But from that point, USC closed on a 24-9 run, shooting 10 for 18 from the floor, to take a 27-20 lead on a three-point jumper by freshman guard Maurice Jones with 2:35 left before halftime.

The Trojans led 35-27 at halftime and opened the second half on a 15-4 run, taking a 50-33 lead with 13:07 left.

The most impressive part about USC's win was that it was done behind a struggling performance from its most productive player, junior forward Nikola Vucevic, who entered the game averaging 17.7 points and 10.3 rebounds.

Saddled by two fouls in the first half, Vucevic didn't make his first field goal until 17:03 in the second half, but then he picked up his third foul at the 15:59 mark. He checked out of the game after that and returned later when senior guard Marcus Simmons left with four fouls.

Vucevic finished with seven points and four rebounds.

USC took its first double-digit lead on a dunk from senior forward Alex Stepheson with 16:49 in the second half. The Trojans improved to 11-1 when Stepheson has a double-double; he finished with 14 points and 16 rebounds.

California freshman guard Allen Crabbe, the Pac-10 freshman of the year, hit a three-point jumper with 6:42 left to cap a 10-2 run that pulled the Golden Bears to within 10, but USC went on a 5-0 run after that to help keep the Golden Bears at a decent distance.

Crabbe, who didn't play the last times the two teams met -- a 78-75 USC win in Berkeley last month -- because of a concussion, finished with a game-high 21 points.